The present invention relates generally to vehicles and, more particularly, to trim components utilized within vehicles.
It is generally considered desirable to reduce the level of noise within a vehicle passenger compartment. External noises, such as road noise, engine noise, vibrations, etc., as well as noises emanating from within passenger compartments, may be attenuated through the use of various acoustical materials. Accordingly, sound attenuating materials for vehicles, such as automobiles, are conventionally used in the dashboard, in conjunction with carpeting for floor panels, in the wheel wells, in the trunk compartment, under the hood, and as part of the headliner.
The attenuation of external noise is conventionally referred to as sound transmission loss (STL). The attenuation of internal noise is conventionally referred to as sound absorption. The acoustic impedance of a material is defined as material density times acoustic velocity, and is expressed in units of Rayls (Newton-seconds/meter3). Acoustic impedance defines how easy it is for air to move through a material. Thus, for fibrous materials, acoustic impedance depends upon the density of the fibrous material and fiber diameter. Generally, the heavier the blanket and the finer the fibers, the higher the acoustic impedance. Moreover, thicker layers typically have more acoustic impedance than thin layers. The ability of a material to attenuate noise is conventionally defined by the material""s STL, acoustic impedance, and absorption characteristics.
Carpeting used to cover the floor areas of vehicles, such as automobiles, is conventionally molded into a non-planar three dimensional contoured configuration which conforms to the contours of the vehicle floor so as to fit properly. In order to make the carpeting moldable and shape-sustaining, it is conventionally provided with a backing of thermoplastic polymer composition. The thermoplastic polymer backing also serves as a barrier to improve the sound deadening properties of the carpet assembly.
Dash insulators are often mounted to a vehicle firewall which separates the passenger compartment from an engine compartment. Dash insulators are designed to reduce the transmission of noise and heat from the engine compartment into the passenger compartment. Conventional dash insulators consist of an acoustical absorber such as an open-cell polyurethane foam or a resinated fiber pad which faces the fire wall, and a barrier sheet such as a heavily filled thermoplastic material. Dash insulator barriers are conventionally produced in a compounding process followed by an extrusion or calendaring process or by an injection molding process to achieve a barrier sheet of desired thickness and width.
FIG. 1 illustrates a conventional dash insulator 10 for reducing noise and heat transmitted from an engine compartment of a motor vehicle 12 into a passenger compartment. The dash insulator 10 is adapted to be mounted inside the passenger compartment of the vehicle against substantially the width of a fire wall 14 that separates the engine compartment from the passenger compartment.
Vehicle instrument panels are generally located behind the steering wheel of a vehicle and include a number of gauges or other displays for providing a driver with information about vehicle conditions. In addition, air vents for distributing cooled and heated air throughout a passenger compartment are often mounted within an instrument panel. Instrument panels are conventionally mounted onto a vehicle firewall with the dash insulator disposed therebetween. FIG. 2 illustrates a conventional instrument panel 20. The illustrated instrument panel 20 includes an instrument cluster area 22, air vents 24, central console area 26 and glove box 28.
FIG. 3 illustrates a conventional automotive carpet assembly 30. The illustrated carpet assembly 30 has a nonplanar three dimensional molded configuration adapted to fit in the front seat compartment of an automobile and includes a raised medial portion 31 adapted to conform to the transmission hump, generally vertically extending side portions 32 adapted to fit beneath the door opening, and a front portion 33 adapted to fit along the inclined floorboard and portions of a vehicle firewall. Various openings or cut-outs are provided, as indicated at 34, to receive air conditioning equipment, the steering column, pedals and the like.
During vehicle manufacturing, dash insulators, instrument panels and floor coverings are typically installed separately. In addition, the installation of dash insulators, instrument panels and floor coverings can be complex and labor intensive. As such, vehicle manufacturers are continuously looking for ways to reduce costs and complexity associated with vehicle manufacturing.
U.S. Pat. No. 4,597,461 to Kochy et al. describes a pre-assembled module for the cockpit zone of a motor vehicle, which is adapted to be mounted as one single unit inside the vehicle body and which incorporates essentially the following components: an instrument board including all instruments and accessories commonly contained therein, fuse box and electric wiring, heater with controls and air distribution system; furthermore a steering system including steering wheel, steering column enclosure and steering support means; also pedals for clutch and brake, including mounting brackets. The vehicle body includes a fire wall and fire wall support member to which the aforementioned components and accessories are connected when in the installed position. The fire wall and fire wall support member are separated from the body shell and serve as an assembly base for the unit. In the installed position, the fire wall and fire wall support member are sealingly connected with the respective adjacent body panels.
In view of the above discussion, vehicle cockpit assemblies and methods of installing same within vehicles are provided. According to embodiments of the present invention, a vehicle cockpit assembly includes a dash insulator that is configured to be attached in face-to-face contacting relationship to a vehicle firewall, an instrument panel attached to the dash insulator, and a floor covering (e.g. molded carpet assembly) also attached to the dash insulator. The dash insulator includes a substrate having opposite first and second surfaces and opposite first and second edge portions. A plurality of apertures are formed through the substrate, each of which is configured to overlie a respective opening in a vehicle firewall when attached thereto. Each aperture is configured to sealably receive an item (e.g., air conditioning equipment, steering column, pedals and the like) extending therethrough between the engine and passenger compartments such that substantially no gaps exist between the item and the substrate. Polyurethane (or other sound attenuation material) may be added to one or more selected portions of the substrate first and/or second surfaces. The polyurethane may be configured to reflect and/or absorb sound directed to the dash insulator.
The instrument panel is attached to the substrate first edge portion. Preferably, the instrument panel and dash insulator are movably attached to each other to facilitate installation thereof within a vehicle. The floor covering is attached to the dash insulator substrate second edge portion. Preferably, the floor covering and dash insulator are movably attached to each other to facilitate installation thereof within a vehicle.
According to embodiments of the present invention, a vehicle cockpit assembly includes a dash insulator having two, separate portions: an upper substrate having opposite first and second surfaces and opposite first and second edge portions, and a lower substrate having opposite third and fourth surfaces and opposite third and fourth edge portions. An instrument panel is attached to the upper substrate first edge portion, and a floor covering is attached to the lower substrate fourth edge portion.
According to embodiments of the present invention, the instrument panel is movably attached to the upper substrate first edge portion such that movement of the instrument panel relative to the upper substrate facilitates installation of the cockpit assembly within a vehicle passenger compartment during vehicle assembly. Similarly, the floor covering may be movably attached to the lower substrate second edge portion such that movement of the floor covering relative to the lower substrate facilitates installation of the cockpit assembly within a vehicle passenger compartment during vehicle assembly. The upper and lower dash insulator substrates are configured to be joined together along the respective second and third edge portions. Upon installation of the upper and lower substrates within a vehicle, the respective second and third edge portions are joined together.
According to embodiments of the present invention, operations for installing a vehicle cockpit assembly within a passenger compartment of a vehicle include providing a dash insulator that is configured to be attached to a vehicle firewall, attaching an instrument panel to an upper portion of the dash insulator, attaching a floor covering to a lower portion of the dash insulator, ascertaining acoustic properties of the vehicle to identify portions of the dash insulator requiring sound reflection and/or absorption, applying sound reflection and/or absorption material to identified portions of the dash insulator, and installing the cockpit assembly within a vehicle.